Not exactly easy listening, but worth it for the historical value. It's like the birth of "space". A very good sounding recording, especially considering the lineage. The amount of work you put into this shows, sir. Never knew this existed, but a search revealed this info from
http://deadessays.blogspot.com/2010/07/constanten-on-constanten.html :
I got back to the States in 1964 I moved to the Bay Area."
"Phil and I had our first LSD from the same batch in early '64, when it still came on sugar cubes."
"I played with Phil, most notably at a 1964 concert, under the auspices of the San Francisco Mime Troupe, that featured Phil, Steve Reich, and me. Phil contributed a quasi-concerto for prepared piano called 6 7/8 for Bernardo Moreno, with me on piano. We gave four performances, each unique (although the third night was especially magical, in my memory)."